In a 1-l. Erlenmeyer flask provided with a mechanical stirrer are placed 75 g. (1 mole) of glycine(Org. Syn. Coll. Vol. I, 1941, 298) and 300 cc. of water. The mixture is stirred vigorously until the glycine is almost completely dissolved, when 215 g. (2 moles) of 95 per cent acetic anhydride(Note 1) is added in one portion. Vigorous stirring is continued for fifteen to twenty minutes, during which time the solution becomes hot and acetylglycine may begin to crystallize. The solution is placed in the refrigerator(Note 2) overnight to effect complete crystallization. The precipitate is collected on a Büchner funnel, washed with ice-cold water, and dried at 100–110°. This product weighs 75–85 g. and melts at 207–208°. The combined filtrate and washings are evaporated to dryness under reduced pressure on a water bath at 50–60°. The residue on recrystallization from 75 cc. of boiling water yields a second fraction, of 20–30 g., which melts at 207–208° after being washed with ice-cold water and dried at 100–110°. An additional 4–6 g. of only slightly less pure product may be obtained from the mother liquor by concentration. The total yield is 104–108 g. (89–92 per cent of the theoretical amount) (Note 3).

2. Notes

1.
The equivalent quantity of 90 per cent acetic anhydride may be used.

2.
The refrigerator used by the checkers maintained a temperature of 5–7°.

3.
The method may be employed to acetylate most α-amino acids with only slight modifications depending upon the solubility of the particular amino acid. When optically active amino acids are acetylated, there is little or no racemization.1

3. Discussion

Acetylglycine has been prepared by the interaction of acetyl chloride and the silver salt of glycine in dry ether or benzene;2, 3 by the action of acetic anhydride on glycine suspended in warm benzene;3 by heating glycine with acetic anhydride;4 by treating an aqueous solution of glycine or its sodium salt with ketene;5 and by treating an aqueous alkaline solution of glycine with acetic anhydride.6

The procedures on this site are intended for use only by persons with prior training in the field of organic chemistry.
These procedures must be conducted at one's own risk. Organic Syntheses, Inc., its Editors, who act as checkers,
and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures
and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures
herein.

I have read and acknowledge that I have training in the field of organic chemistry
and that Organic Syntheses does not warrant or guarantee safety in the use of these procedures.

No part of this Website or Database may be reproduced, stored in a
retrieval system or transmitted
in any form or by any means, electronic, mechanical, photocopying,
recording, scanning or
otherwise, except as permitted under Sections 107 or 108 of the 1976
United States Copyright
Act.